[FIX] website_sale_stock_wishlist: cart out of stock

Current behaviour:
When unticking "Continue selling if out-of-stock" on
a storable product, if added on wishlist, product
can still be added to cart.

Expected behaviour:
Out-of-stock products should not be added to cart

Steps to reproduce:
1. Create a storable product
2. Deactivate the "Continue selling if out-of-stock" setting
3. Go to the product selling page, cannot be added to cart
4. Add the product to your wishlist
5. Go in the wishlist
6. The product can be added to the cart

Fix:
Fixed in 16.0, backport of 16.0

opw-3283025

closes odoo/odoo#121542

Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

addons/website_sale_stock_wishlist/views/templates.xml

@@ -10,5 +10,8 @@
                 <small><i t-attf-class="fa #{'fa-check-square-o' if notify else 'fa-square-o'}"></i> Be notified when back in stock</small>
             </button>
         </xpath>
+        <xpath expr="//button[hasclass('o_wish_add')]" position="attributes">
+            <attribute name="t-att-disabled">not wish.product_id.allow_out_of_stock_order and wish.product_id._is_sold_out()</attribute>
+        </xpath>
     </template>
 </odoo>